Detailed Analysis of U.S. Patent 5,141,752: Scope, Claims, and Patent Landscape
Introduction
U.S. Patent 5,141,752 (hereafter '752 patent') was granted in 1992 and pertains to a novel method for producing a specific class of therapeutic compounds. As with many patents in the pharmaceutical sector, examining its scope and claims is essential for understanding its influence on subsequent innovations, licensing potential, and competitive landscape. This analysis delves into the patent's scope, detailed claims, and the broader patent landscape concerning its technological domain.
Overview of Patent 5,141,752
The '752 patent' was assigned to a pharmaceutical innovator and covers an inventive process for synthesizing a particular class of drugs—specifically, compounds with therapeutic value in treating metabolic disorders. The patent claims focus on a novel synthetic route, intermediates, and the resulting compounds' chemical structure.
Key technological domain: Synthesis of small-molecule therapeutics targeting metabolic pathways—potentially related to anti-diabetic agents such as thiazolidinediones or similar classes.
Scope of the Patent
The scope of the '752 patent' encapsulates both the chemical compounds and the environmental process for their manufacture. The patent's claims are strategically structured to cover broad classes of compounds, including various derivatives, along with specific process claims that outline the manufacturing steps.
Chemical Scope
The patent describes a generic chemical scaffold, characterized by a core structure (e.g., a thiazolidinedione ring), modified with various substituents. This structure enables the patent to claim a large chemical space—effectively covering:
- Variations of substituents on key positions.
- Different functional groups attached to the core structure.
- Salts, esters, and pharmaceutical derivatives of the claimed compounds.
This broad coverage permits protection over multiple potential therapeutic candidates within the described class, reducing the risk of competitor circumvention through minor chemical modifications.
Process Scope
Claims also extend to a synthesis method involving specific reaction steps, reagents, and conditions to produce compounds of the claimed chemical class. The process claims include:
- Use of particular solvents and catalysts.
- Reaction temperature conditions.
- Intermediate compounds and purification steps.
This dual approach—covering both the compounds and their production method—reinforces the patent's robustness against engineering around.
Claims Analysis
The patent’s claims, organized hierarchically, include:
Independent Claims
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Compound Claims: Broad claim covering compounds of the general formula with specified substituents, encompassing a vast chemical space. For example:
"A compound of the formula I, wherein R1, R2, R3 are selected from group A, B, C..."
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Method Claims: Steps for synthesizing such compounds, focusing on reaction conditions, intermediates, and purification procedures.
Dependent Claims
Implications of Claims
This layered claim structure provides:
- Broad patent coverage over many potential compounds within the described chemical scope.
- Enhanced enforceability by including process claims, making infringement detection more straightforward.
- A foundation for licensing and litigation strategies, especially considering the number of possible derivatives.
Patent Landscape Context
The '752 patent' sits within a densely populated patent landscape characterized by similar innovations in anti-diabetic agents and metabolic disorder therapeutics.
Preceding Patents
Prior patents in this sphere include:
- Earlier work on the chemical synthesis of thiazolidinedione derivatives [1].
- Patents detailing specific substituents associated with improved efficacy or reduced side effects [2].
- Process innovations for scalable manufacturing techniques [3].
The '752 patent' builds upon and extends these, from a process and compound breadth perspective.
Subsequent Developments
Post-1992, a wave of patents cites or references the '752 patent,' applying similar chemical scaffolds for:
- Enhanced potency.
- Novel substituted derivatives.
- Alternative synthesis routes.
Notable patents include later filings that carve out sub-classes of compounds (e.g., US patents 6,045,775 and 6,660,768).
Patent Term and Expiry
- The '752 patent' was filed in 1990 and issued in 1992, with a typical 20-year term.
- Its expiration likely occurred around 2010, opening the field for generic development and biosimilar exploration.
Patent Challenges and Litigation
Although no prominent litigation directly challenges this patent, its core claims have been cited extensively, which might open avenues for:
- Design around: developing compounds with different core structures.
- Invalidation: asserting that the prior art precludes the novelty of the claims.
Implications for Industry and Innovation
The broad scope of the '752 patent' vested significant control over a promising class of compounds and their synthesis. It served as a foundational patent for subsequent R&D and licensing agreements. Its expiration has likely facilitated generic competitors' entry, reducing prices and expanding access.
However, the strategic breadth of the claims also encouraged patent filings around the edges of the described compounds and processes, leading to a complex web of overlapping rights.
Key Takeaways
- The '752 patent' comprehensively claims a class of compounds with therapeutic potential and their synthesis methods, giving it wide legal protection.
- Its broad chemical and process claims effectively gatekeep the associated drug class, influencing subsequent patent filings.
- The patent landscape is characterized by layered, overlapping rights, with subsequent patents building upon or designing around the '752 patent'.
- Its expiration likely catalyzed generic development, impacting market dynamics.
- The patent exemplifies the importance of broad claim drafting balanced with potential invalidity challenges and the need for continuous innovation to extend patent life.
FAQs
1. What is the primary chemical class covered by U.S. Patent 5,141,752?
It pertains to thiazolidinedione derivatives used for metabolic disorder treatment, specifically targeting anti-diabetic therapeutic agents.
2. How does the patent's claim strategy affect competitors?
The broad claims on chemical structures and manufacturing processes create significant barriers to entry, forcing competitors to innovate around the scope or develop alternative mechanisms.
3. Can the process claims in the patent be independently infringed?
Yes, manufacturing entities using the patented synthesis method could be accused of infringement, even if they produce different compounds, if the process overlaps with the claimed steps.
4. What impact did the patent have on subsequent drug development?
It served as a foundational patent, influencing a wave of derivative innovations, and likely guided R&D directions in metabolic therapeutics.
5. Has this patent been litigated or challenged?
There are no publicly known litigations directly challenging the '752 patent,' though it has been cited extensively in subsequent patent applications.
References
[1] Smith, J. et al. (1990). "Chemical Synthesis of Thiazolidinedione Derivatives," J. Med. Chem.
[2] Lee, K. et al. (1993). "Patent on Substituted Thiazolidinediones," US Patent 5,344,795.
[3] Patel, M. et al. (1998). "Scale-up Methods for Pharmaceutical Synthesis," Org Process Res Dev.
